maxim



' 2 Sheets--Sheet 1. H. S. MAXIM.

ELECTRIC LAMP.

No. 252,840. Patented Jan. 24,1882.

TERS. Phomlmuognpher. wnlhmgmn. av 04 2 S.heets-Sheet 2. H. S. MAXIM.

ELECTRIC LAMP.

No. 252,840. Patented Jan. 24,1882,

I I I aaIII'IIIIl/IllIl/IIIIIIC I: 4

Fig:

&

Wilt Please? N. PETERS, Pbolo-Li\hognpher. Washluglnn. n. c.

UNITED STATES PATENT OFFICE.

TO THE UNITED STATES ELECTRIC LIGHTING COMPANY, OF NEW YORK, n. Y.

ELECTRIC LAMP.

SPECIFICATION forming part of Letters Patent No. 252,840, dated January 24, 1882.

Application filed December 27, 1879. Patented in England April 21, 1880.

To all whom it may concern Be it known that I, HIRAM S. MAXIM, of the city'of Brooklyn, county of Kings, and State of New York, have invented a new and useful Improvement in Electric Lamps, of which the following is a specification, reference being bad to the accompanying drawings, which form a part hereof.

My invention relates especially to the class of electric lamps known as hanging lamps, in which the clock-work or other machinery for feeding the carbons is located in a case above the focus; and it consists in an improved method of regulating such feeding mechanism, and in an improved construction of the part of the lamp carrying the lower carbon and the globe.

In lamps as heretofore made the regulator has not been sufliciently sensitive, as it has required too great a change in the strength of the current to cause it to act, and this has been the cause of unsteadiness in the light. In order to obviate this I have removed all friction from the regulating device by suspending the working parts upon springs, which at the same time support the upper carbon and its feeding mechanism free from contact with all other parts of the lamp, and serve as frictionless conductors of the current to the carbon-holder. Lamps as heretofore constructed have also been subject to another difficulty. It is frequently necessary toremove the globe in order to perfectly adjust the carbons when they are first put in, and insuch lamps no means has been hitherto provided for setting or removing the globe when the carbons are of full length and adjusted, without disturbing their adjustment. To obviate this difficulty Irnake the side rods which carry the globe-holder telescopic.

In the drawings, Figure l is a front elevation of a lamp constructed inaccordance with my invention. Fig.2 is a side elevation; and Fig. 3 is a central vertical section of the upper part of the same, showing the feeding 1nechanism and regulator. Figs. 1 and2 are upon the same scale, but Fig. 3 is considerably enlarged to show in a better manner the construction of the parts.

Similar letters of reference indicate like parts in each.

A is the case containing the feeding mechanism and regulator.

B is an axial magnet or coil, and O theiron core of the same.

D is a brass extension of the magnet-core, screwed into its upper end and extending some distance above it. This extension D carries the train of clock-work E E, and the magnetcore and its extensions are suspended upon the springs'T, T, and I.

E E is a train of clock-work of the usual form used in such lamps, and F is a star-wheel mounted upon the most rapidly. moving shaft, and carrying one or more fans.

G is a stationary detent affixed to the case A.

H is a controlling-clamp or dash-pot connected with the magnet-core and its extension to prevent too rapid movement of the parts.

I is a perpendicularspiral spring hung upon the two adjusting-screws J and K. The nut of the screw K has a fan-shaped projection hearing loosely against the side of the case to keep the spring from turning. The screw K is attached to the case A, and the screw J is attached to a projecting arm, S, of the-magnetcore, so that the spring I tends to support the core with its extension and connected mechanism, and the tension of the spring may be readily adjusted either from above or below.

L is a combined hook and lever, pivoted to the case A and fitted to hook over the projection S, and thus hold up the parts connected therewith. It is fitted with a lever-handle for convenience of manipulation, and has a spring, It, bearing upon it, like the back-spring of a knife, and so arranged that the lever has two positions of restone when the hook is thrown forward and one when it is thrown back.

N is the positive binding-post, and O is the negative. The positive wire is carried from between the parts. The binding-post O is electricallyconnected with the lowercarbon holder by the side rod,d, and the globe-holder X.

P and Q are set-screws to limit the vertical movementof themagnet-core and its connected parts.

T Tare flat horizontal springs, attached at one end to the case A and at the other to projections S S, afiixed to the magnet-core and its extension. (I (l are side rods attached to the case A with a joint of insulating ma erial, and supporting the globe-holder X X. These rods are made hollow, and other rods rigidly attached to the globe-holder are inserted in them longitudinally. This construction is best shown at the right in Fig. 1, where the rod 01 is represented as cut away. 0 isthe interior rod, and a is a head attached to it to bear against an interior shoulder at the lower end of d and prevent an entire separation of the parts.

U U are short projections on the rods (1 d, beveled on their lower sides, and V V are spring-catches hinged to the globe-holder, which hook over the projections U U and hold up the globe-holder. The lower rod may be made the outside one, if desired, and I do not consider the particular form or location of the fastening ess Iijlfll, although the ones shown are effective and convenient.

The lower part of the upper-carbon holder is made with aball-and-socket joint, with part of the socket formed of a nut, M, so that the carbon may be readily adjusted as regards direction, and secured firmly in position by turning the nut. The upper-carbon holder is carried by a spindle, W, passing longitudinally through the ma gnet-core audits extension. It has a rack on one side, which engages with a small pinion-of the train of clock-work on the shaft having the slowest movement, but otherwise is free to move longitudinally.

The lamp is suspended in any desired location by means of the support Y, which is made in tubular form and incloses the upper end of the spindle W. When the spindle is raised it occupies the recess within the support, as shown in Fig. 3. In this way the upper-carbon carrier is protected from dust and accidental injury, and the construction of the lamp is made compact and convenient.

The operation of the lampis as follows: The magnet-core O and its extension D have a free vertical motion within the coil B, and are suspended upon thehorizontalflat springsTT and the spiral spring I, and as the magnet-core is located somewhat lower down than its coil it constantly tends to rise when the coilis excited by a current of electricity. The spindle IV is supported by the train of clock-work only, and its weight is so adjusted that it will descend slowly when the gearing is free to move. The tension of the supportin g-sprin gs is so adjusted to the weight of the magnet-core and the parts which it carries that the train of gearing shall hang just low enough to clear the detent G whena currentof ordinary strength is passing. The gearing then slowly turns and the spindle W descends, bringing the carbons together to supply the consumption at the focus. If the points approach too closely to each other, the current increases in strength, the magneteorc is drawn in, the upper carbon is retracted, and the feeding mechanism is arrested by the detent G. If, on the other hand, the points hecome too widely separated, the current is weakened, the magneteoil loses its power, and the core descends and advances the upper carbon. At the same time the gearing is released from the detent and the feeding process proceeds.

The apparatus may be adjusted with very great nicety by means of the adjusting-screws J and K and the spring I, and as the moving parts are freely suspended and nicely balanced upon the supportingspring, a very slight change in the current passing through the coil 'is sufficient to bring the gearing into contact with the detent or to release it. \Vhenever it is desired to stop thelightthe hookLis sprung over the arm S and the feeding mechanism is by one operation retracted and locked.

Whenever it is necessary to renew the carbons the spindle W is pushed up (a ratchet in the gearing allowing it to move upward freely) and the globe is removed. When the new carbons are adjusted to position the globe-holder is depressed by pressing down the catches V V and drawing out the telescopic side rods, the globe is replaced over the lower carbon, and the globeholder returned' to its former position without disturbing the adjustment of the carbons.

It is evident that the construction of the different parts may be considerably varied without essential change in the apparatus. Instead of the magnet A with a movable core, one or more eleetro-magnets with fixed cores and movable armatures may be used, and the spring I may be dispensed with by applying a tensionadjuster to one or both of the other springs. Other forms of feeding devices than a rack and train of gearing may probably be adapted to be stopped and started by slightvertieal movement of their supports. I consider all such constructions as within my invention.

I am awarethat trains of gearing in connection with detents of various forms operated by electro-magnetsplaced in the eircuithave heretofore been used in such lamps for feeding the upper carbon to the focus and regulating its motion, and I do not claim such combination of parts irrespective of the particular devices hereinbefore set forth; but,

Having described my invention, whatIclaim as new, and wish to secure by Letters Patent, is-

1. The combination,in an electric lamp, ofa gravitatin g carbon carrier, with an axial magnet having a hollow core surrounding the carbon-carrier, a train of gearing mounted upon said core and controlling the descent of the carbon-carrier and a fixed detent into engagementwithwhich the gearing is brought by the movement of the magnet-core,substantially as described.

2. The combination, in an electric lamp, ofa

v movable magnet core surrounding a gravitatthe springs T T, suspending said core free from 5. The combination, in an electriclamp, ot'a movable magnet-core hung on springs and carryingthe carbon feeding and regulating devices, with the hook L for locking the same, substantially as described, and for the purposes set forth,

6. In an electric lamp, the combination,with the upper and lower carbons, of a sectional frame, one yciiion carrying the up eicarbon the other portion carrying the lower carbon, and the globe, the two sections beingadjustable in the direction of the length of the carbons, so as to lengthen or shorten the lamp-frame, substantially as set forth.

7. The combination, with the upper-carbon carrier, its feeding mechanisn1,and supporting frame, of a tubular support attached to and adapted to sustain the lamp from above, extending above the case or frame in line with the carbon-carrier, so as to receive and inclose the la'ter.

HIRAM s. MAXIM.-

Witnesses:

Grms. G. OLAGGETT, LEONARD E. OUR'rIs. 

